The present invention relates to an irrigation system and, in particular, it concerns a modular segmented irrigation system for a variable rate drip irrigation.
In the field of drip irrigation, there is a natural tendency towards non-uniform release of water along the length of an irrigation tube due to variations in supply pressure. Pressure loss due to energy losses may result in an uneven discharge along the length of a tube. The common approach to ensuring a roughly uniform distribution of water along the length of the system usually involves installation of pressure-regulating drip emitters on the tube wall. Installation of pressure-regulating drip emitters may contain many drawbacks associated with already existing systems. Such customization significantly increases the overall cost of a system based on the system's specific manufacturing requirements and the technical expertise required for a proper installation. The installation process of the pressure regulating emitters is complicated by the need to deploy such components along the existing tube while ensuring that the perforation along the tube wall is spatially coordinated with the emitter positions. An improper placement of emitters may significantly decrease system performance or even render it inoperable. Furthermore, utilizing such drip emitter does not address the problem of sectional irrigation, wherein certain crop along the irrigation system may requires more water than others.
Similarly, retrofitting an existing system to segment specific irrigation may rely heavily on the utilization of electronic controls. Such approach usually requires a complete replacement of existing valves and tubing elements, in turn, significantly increasing the cost of implementation. The arrangement of conventional segment specific irrigation systems is both, complicated and expensive due to the underground distribution of electrical wiring along the water distribution network. Typically, this power comprises 110 AC, which must be converted into direct current potentials in order to power the communication subsystems of the receivers and the remote controlled valves. Implementing electrical control may also double the number of valves required for directional control within the system. For example, a conventional segment specific system may require four valves for each segment in order to direct the water flow between individual segments. Such implementation is likely to include a set of inlet and outlet valves placed on each end of individual segment, leading to a significant increase in the overall cost.
Utilization of a segment specific irrigation system on a typical 18 hole golf course may require between 1000 and 1500 remote control valves in order to provide sufficient water delivery. Proper cable installation on such a system may require between 100,000 to 500,000 feet of wire, further increasing the system cost, and complexity of installation.
Due to the limitations of existing systems, various other attempts have been made to provide uniform flow to a specific segment within a system. An alternative approach to segment specific irrigation is the use of porous-wall irrigation tubes. These tubes are particularly implemented in a subterranean use due to their porous properties. The porous sidewalls are not compromised by the presence of mud and dirt, and therefore offer advantages of reduced evaporation losses, and proximity to the roots. However, such porous irrigation tubes also suffer from a pronounced problem of non-uniform flow rates, with greater amounts of water being released towards the higher pressure supply end of the line than the segments towards the end of the system. The difficulty in repairing and maintaining a subterranean system may also serve as a deterrence in implementation of such systems.
There is, therefore, a well defined need in the art for a modular segment specific irrigation system, implementing a manufactured tube structure with less elements while producing relative uniform release of water along the length of the segment, wherein the system can be easily adjusted according to the crop's growth cycle.